[chrisdirkis]

If everything links to everything, that's an n^2 problem (and hard to coordinate actors to do). If everything just links to one service, that's n or 2n at most.

Also, I can write the name of any twitter account in my HN profile. I can only link _my_ twitter account to a keybase account I own.

[Spivak]

Right, but if your Twitter account links to your HN account then you've proven ownership both ways. If you don't want the n^2 problem then just have a list of all your accounts on one site and link there. Say, for example, your Mastadon account.

[Nadya]

I solved that problem that way too: https://nadyanay.me/identities.html

It comes with some issues, namely that I suck at keeping it up to date and that not all identities I would like to list there have a way for me to provide proof beyond my word alone. For most use cases and attack vectors I consider this sufficient enough. Now this is outside most peoples' threat models, but Keybase also provides some mitigation against some other scenarios.

1) If nadyanay.me becomes compromised the imposter could update /identities.html with a new and fake list and I would need to update my link everywhere it is used or I would be pointing people to the imposter list. I have more faith in both (a) Keybase is less likely to be compromised and (b) in the event Keybase has become compromised someone will notice. Nobody would notice if my personal site was compromised, as even my closest friends don't regularly browse my website. It could honestly take weeks or even months to discover the file had been changed.

2) A person who compromises my account(s) must also have access to my private key in order to sign messages in my name. This is important because even if any of my accounts is compromised they're still unable to prove they are me if asked. This is something I actively practice with a few online friends of mine. We pretty regularly lend large sums of (virtual) game cash to one another worth in the range of $10,000-$15,000 USD if RWT'd. The last thing either of us would want is an imposter asking to borrow some money in-game from them and selling it off and so anytime we ask to borrow some in-game cash we ask to see a signed message. I admit that's the primary reason behind most of my signed messages...

3) Any attempts at creating a new key will allow users to see that my key has been revoked and replaced. Users who had signed my old key would need to re-verify with me that my new key is valid. Social engineering and people's casual use cases means the imposter would just claim to be me and most people would believe them. Few would bother verifying but it at least provides an additional opportunity for the imposter to be outed.